This invention relates to a system for controlling plural engines in a power plant and, more particularly, to a control circuit for assuring that power provided to a common load is properly shared by the engines.
Output shafts of plural engines are often interconnected to provide isochronous operation and to provide power to a common load. A control system is usually provided to equally divide the load between the two engines. Since the engines are made to operate at a common speed, the load is balanced or equally shared by increasing or decreasing the torque output from each engine. Most control systems are of the hydraulic or pneumatic type. Prior art systems for load sharing of coupled engines employ droop control wherein the output of the engine providing less than its share of torque is increased to match the output torque provided by the other engine.
Helicopter power plants often employ two similar engines, as gas turbine engines which, coupled together for isochronous operation, provide power to a common load. The most efficient operation of the plant is realized when each engine is supplying its half of the torque requirement.